21969396 has 36 divisors (see below), whose sum is σ = 58458400. Its totient is φ = 6937488.

The previous prime is 21969371. The next prime is 21969397. The reversal of 21969396 is 69396912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21969397) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15376 + ... + 16743.

Almost surely, 2^21969396 is an apocalyptic number.

It is an amenable number.

21969396 is an abundant number, since it is smaller than the sum of its proper divisors (36489004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21969396 is a wasteful number, since it uses less digits than its factorization.

21969396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32148 (or 32143 counting only the distinct ones).

The product of its digits is 157464, while the sum is 45.

The square root of 21969396 is about 4687.1522270991. The cubic root of 21969396 is about 280.0739430563.

The spelling of 21969396 in words is "twenty-one million, nine hundred sixty-nine thousand, three hundred ninety-six".